Integrated circuit having a comparator circuit including at least one differential amplifier

An integrated circuit including a comparator circuit and a vertical voltage control switch element formed on a single substrate. The comparator circuit including a differential amplifier circuit having a current mirror circuit M, a differential amplifier circuit D 1 with two current paths L 1 and L 2 , and an inverter INV. The output section of the current mirror circuit M is used as a constant current source for the differential amplifier circuit. The current mirror circuit M includes a load MOS transistor 1, a MOS transistor 2 constituting an input section, and a MOS transistor 10 constituting an output section. The current path L 1 of the differential amplifier circuit D 1 includes a load MOS transistor 11, an amplifying depletion type MOS transistor 13, and an input terminal in 1. Similarly, the current path L 2 includes a load MOS transistor 12, an amplifying depletion type MOS transistor 14, and an input terminal in 2. The inverter INV is constructed with a load MOS transistor 3 and a switching transistor 4.